Bring a large pot of salted water to a boil. Add the pasta and cook according to the package directions until al dente. Drain and set aside, tossing lightly with butter or oil to prevent sticking.

In a large saucepan, melt 2 tablespoons of butter over medium heat. Whisk in the flour to create a roux and cook for 1–2 minutes to remove the raw flour taste.

Gradually add the milk and heavy cream while whisking continuously. Stir until the mixture thickens and becomes smooth, about 5–7 minutes.

Lower the heat and begin adding the shredded cheeses a handful at a time—cheddar, mozzarella, and pepper jack—stirring until melted and creamy.

Season the sauce with salt, black pepper, garlic powder, onion powder, smoked paprika, and ground mustard if using. Stir until evenly combined.

Add the cooked pasta to the cheese sauce and gently fold until every piece is coated. Taste and adjust seasonings as needed.

For a baked version, preheat the oven to 375°F (190°C). Pour the mac and cheese into a greased baking dish.

In a small bowl, mix breadcrumbs with melted butter and sprinkle evenly over the top. Bake for 20–25 minutes, or until golden and bubbly.

Remove from the oven, cool slightly, and garnish with chopped parsley before serving.